So it turns out that -- title notwithstanding -- Beth Shapiro’s How to Clone a Mammoth: The Science of De-Extinction (Princeton University Press) is not a do-it-yourself manual. What’s more, cloned mammoths are, in the author’s considered opinion, impossible. Likewise, alas, with regard to the dodo.
But How Not to Clone a Dodo would never cut it in the marketplace. Besides, the de-extinction of either creature seems possible (and in case of the mammoth, reasonably probable) in the not-too-distant future. The process involved won’t be cloning, per se, but rather one of a variety of forms of bioengineering that Shapiro -- an associate professor of ecology and evolutionary biology at the University of California at Santa Cruz -- explains in moderate detail, and in an amiable manner.
Her approach is to present a step-by-step guide to how an extinct creature could be restored to life given the current state of scientific knowledge and the available (or plausibly foreseeable) advances in technology. There are obstacles. Removing some of them is, by Shapiro’s account, a matter of time and of funding. Whether or not the power to de-exterminate a species is worth pursuing is a question with many parts: ethical and economic, of course, but also ecological. And it grows a little less hypothetical all the time. De-extinction is on the way. (The author allows that the whole topic is hard on the English language, but “resurrection” would probably cause more trouble than it’s worth.)
The subject tickles the public’s curiosity and stirs up powerful emotions. Shapiro says she has received her share of fan and hate mail over the years, including someone’s expressed wish that she be devoured by a flesh-eating mammal of her own making. Perhaps the calmest way into the discussion is by considering why reviving the mammoth or the dodo is possible, but would not be the same thing as cloning one. (And dinosaur cloning is also right out, just to make that part clear without further delay.)
To clone something, in short, requires genetic material from a living cell with an intact genome. “No such cell has ever been recovered from remains of extinct species recovered from the frozen tundra,” writes Shapiro, whose research has involved the search for mammoth remains in Siberia. Flash freezing can preserve the gross anatomy of a mammoth for thousands of years, but nucleases -- the enzymes that fight off pathogens when a cell is alive -- begin breaking down DNA as soon as the cell dies.
What can be recovered, then, is paleogenetic material at some level of dismantling. The challenge is to reconstruct an approximation of the extinct creature’s original genome -- or rather, to integrate the fragments into larger fragments, since rebuilding the whole genetic structure through cut-and-paste efforts is too complex and uncertain a task. The reconstituted strings of genetic data can then be “inserted” at suitable places in the genome of a related creature from our own era. In the case of the woolly mammoth, that would mean genetic material from the Asian elephant; they parted ways on the evolutionary tree a mere 2.5 million years ago. In principle, at least, something similar could be done using DNA from the taxidermy-preserved dodo birds in various collections around the world, punched into the pigeon genome.
“Key to the success of genome editing,” writes Shapiro, “has been the discovery and development of different types of programmable molecular scissors. Programmability allows specificity, which means we can make the cuts we want to make where we want to make them, and we can avoid making cuts that kill the cell.”
Cells containing the retrofitted genome could then be used to spawn a “new” creature that reproduces aspects of the extinct one -- pending the solution of various technical obstacles. For that matter, scraping together enough raw material from millennia past presents its own problems: “In order to recover DNA from specimens that have very little preserved DNA in them, one needs a very sensitive and powerful method for recovering the DNA. But the more sensitive and powerful method is, the more likely it is to produce spurious results.”
Also a factor is the problem of contamination, whether found in the sample (DNA from long-dead mold and bacteria) or brought into the lab in spite of all precautions. Shapiro leaves the reader aware of both the huge barriers to be overcome before some species is brought back from extinction and the strides being made in that direction. She predicts the successful laboratory creation of mammoth cells, if not of viable embryos, within the next few years.
It will be hailed as the cloning of an extinct animal -- headlines that Shapiro (whose experiences with the media do not sound especially happy) regards as wrong but inevitable. The reader comes to suspect one motive for writing the book was to encourage reporters to ask her informed questions when that news breaks, as opposed to trying to get her to speculate about the dangers of Tyrannosaurus rex 2.0.
Besides its explanations of the genetics and technology involved, How to Clone a Mammoth insists on the need to think about what de-extinction would mean for the environment. Returning the closest bioengineerable approximation of a long-lost species to the landscape it once inhabited will not necessarily mean a happy reunion. The niche that animal occupied in the ecosystem might no longer exist. Indeed, the ecosystem could have developed in ways that doom the creature to re-extinction.
Shapiro is dismissive of the idea that being able to revive a species would make us careless about biodiversity (or more careless, perhaps), and she comes close to suggesting that de-extinction techniques will be necessary for preserving existing species. But those things are by no means incompatible. The author herself admits that some species are more charismatic than others: we're more likely to see the passenger pigeon revived than, say, desert rats, even though the latter play an ecological role. The argument may prove harder to take for the humbler species once members of Congress decide to freeze-dry them for eventual relaunching, should that prove necessary.
By now we should know better than to underestimate the human potential for creating a technology that goes from great promise to self-inflicted disaster in under one generation. My guess is that it will take about that long for the horrible consequences of the neo-dodo pet ownership craze of the late 2020s to makes themselves fully felt.
The Buddhist idiom “monkey mind” does not require years of contemplation to understand. It explains itself quickly to anyone who attempts the most basic meditative practice: closing the eyes and concentrating solely on the breath. By the second or third exhalation, your attention will have shifted -- if not to an itch, or the aftertaste of your most recent meal, then to some memory, plan, song lyric, etc., and then to another, until you remember to focus on the flow of the breath.
Whereupon it will all start up again. The human mind, in the Buddha’s words, moves “just as a monkey swinging through the trees grabs one branch and lets it go, only to seize another….” The simile is all the more fitting given that he spent years meditating in the forest. (I take it by implication that the mind also makes shrill noises and scratches itself a lot.)
Twenty-five hundred years and a good deal of laboratory research later, Michael Corballis’s The Wandering Mind: What the Brain Does When You’re Not Looking (University of Chicago Press) has little to say about taming, much less transcending, the restless mind. Corballis, a professor emeritus of psychology at the University of Auckland, New Zealand, wants to reconcile us to the mental flux through a review of scientific research on the neurobiology behind ordinary awareness. From his perspective, wandering attention is necessary and even beneficial for humankind, in spite of the disapproval of authority figures for countless generations.
Central to the author’s approach is what he calls “mental time travel” -- meaning, in part, the human ability to remember the past and anticipate the future, but also (more importantly, perhaps) our capacity to shift attention away from immediate experience for considerable periods while focusing on our memories, plans and worries.
This power is a blessing and a curse, and Nietzsche suggested that it gives us reason to envy the beast of the field, which “springs around, eats, rests, digests, jumps up again, and so from morning to night and from day to day, with its likes and dislikes closely tied to the peg of the moment, and thus is neither melancholy nor weary.”
But that’s just human vanity talking. A variety of methods are available to record the flow of blood and bursts of neural activity within the brain -- and some can be used on lab animals as well as hospital patients. Corballis reports on experiments with rats that have learned their way through a maze to a feeding spot. The effort sets off “sharp-wave ripples” among the brain cells dedicated to tracking a rat’s location. But the activity may continue even after the rat is done, “as though the animal is mentally tracing out a trajectory in the maze,” the author says.
Perhaps this is not so surprising, since “for a laboratory rat, being in a maze is probably the most exciting event of the day.” But there’s more:
“These mental perambulations need not correspond to the paths that the rat actually traversed. Sometimes the ripples sweep out in a path that is precisely the reverse of the one the rat actually took. It may be a path corresponding to a section of the maze the rat didn’t even visit, or a shortcut between locations that wasn’t actually traversed. One interpretation is that the ripples function to consolidate the memory for the maze, laying down a memory for it that goes beyond experience, establishing a more extensive cognitive map for future use. But mind wandering and consolidation may be much the same thing. One reason that we daydream -- or even dream at night -- may be to strengthen memories of the past, and allow us, and the rat, to envisage future events.”
On that point, at least, our difference from the humble rodent is one of degree and not of kind: the human brain undertakes (and absorbs information from) a much wider range of activity, but the same part of the brain -- the hippocampus -- serves as the hub for the neural networks that enable “mental time travel.”
What does distinguish us, of course, is language, which among other things enables storytelling and more complex forms of social organization than those possible for even the most sophisticated chimpanzee community. So the human brain finds itself navigating any number of mazes, many of its own creation. Zoning out while someone is speaking, then, is not a solely a function of overburdened powers of attention reaching their limit. The wandering mind is part of a range of phenomena that includes dreaming, fantasy, hallucination and creativity -- all of them products of the brain’s constant obligation to shift between levels of experience and directions of “time travel.”
Corballis makes the point with a range of biological, medical and anthropological references in a casual style that sometimes just barely holds things together. One or two chapters might have been removed without it making much difference, as would the jocular bits about whether the reader is still paying attention. (“Yes,” reads my note in the margin, “because irritation wonderfully concentrates the mind.”)
While interesting on the whole, the book leaves completely unaddressed the question of whether there is any difference between a mind wandering under its own powers, so to speak, and one that’s grown accustomed to constantly increasing bombardment. Where the monkeys used to swing from vine to vine, they now run the risk of colliding in midair, distracted by all the beeps and buzzes coming from their smartphones.
If you have a deep interest in natural history, then chances are Caitlin O’Connell’s name is already familiar. And if not: simply put, she’s like Jane Goodall, but with elephants.
The author’s note for Elephant Don: The Politics of a Pachyderm Posse (University of Chicago Press) identifies O’Connell as author of “the acclaimed science memoir The Elephant’s Secret Sense,” from the same publisher, “and the Smithsonian channel documentary 'Elephant King,’” which I am going to watch just as soon as this column is done. For in fact the topic was of no particular interest to me before noticing Elephant Don, with its arresting and beautifully composed cover photo of several tuskers gathered on a dusty plane in Namibia -- a portrait of “the boys’ club,” as O’Connell dubs a roving group she’s studied in the wild for many years.
Portions of the book are adapted from postings to the New York Times’s Scientist at Work blog that the author wrote while also publishing more technical presentations of her findings in Ethology Ecology & Evolution, American Zoologist and other peer-reviewed journals. When not doing fieldwork in Namibia, O’Connell is an instructor at the Stanford University School of Medicine. Her vita also lists her as co-author (with Donna M. Jackson) of The Elephant Scientist -- an award-winning children’s book -- to which Elephant Don is something like the grown-up’s sequel.
O'Connell's earlier writings, both scientific and popular, reported on research into elephants’ ability to communicate through their feet, via seismic waves. A bull in heat can “hear” the distinctive stomps of an amorous female and make his way in her direction. Elephants do not have a herdwide mating season. Mature individuals of either sex go into heat on their own cycle, for periods of four to six weeks, every five years or so. Without the earthshaking mating call, they might never hook up.
Why not? It’s a matter of gender politics: male offspring have a place in the herd until they reach sexual maturity. The surge of hormones turns the male calf into enough of a pest that the matriarchy pushes him out to fend for himself in a world full of predators and loneliness. (The men’s rights movement would be hard-pressed to adduce a more pitiful injustice.)
Elephant Don chronicles the life and times of a group of adult males who come to Mushara -- the watering hole where the author and her coworkers have established their observation post -- during several summers, beginning in 2005. The size and composition of the cohort change over time, but researchers can distinguish the animals by variations in size, tusk length and ear characteristics -- identifying them by nicknames that seem to become more comical from one year to the next, including Luke Skywalker, Keith Richards, Rocky Balboa and Captain Picard.
The de facto leader of the group -- the one who gets the best spot at the watering hole and decides when it’s time to leave -- is an old bull called Greg, also known as “the don,” for reasons that become clear after he takes his place:
“[The] subordinates line[d] up to place their trunks in his mouth as if kissing a Mafioso don’s ring…. Each bull approached in turn with trunk outstretched, quivering in trepidation, dipping the tip into Greg’s mouth. It was clearly an act of great intent, a symbolic gesture of respect for the highest-ranking male. After performing the ritual, the lesser bulls seemed to relax their shoulder as they shifted to a lower-ranking position within the elephant equivalent of a social club.”
The don bellows and flaps his ears to signal that it’s time to roll, and his loyal subordinates bellow in reply while making sure that the younger bulls don’t fall behind.
Hierarchy and communication are well-established aspects of life in the matriarchal herd, but O’Connell indicates that social order among exiled males is a much less studied topic. She observes other behavior that seems to express or maintain the leadership arrangement, such as one bull turning his back to acknowledge his subordinate position to another, or holding his trunk over a younger or smaller bull’s head, which seems to express camaraderie.
Another set of signs accompany the onset of musth, the mating phase, when a bull’s testosterone level shoots up to 20 times normal. He walks around in a state of constant arousal, dribbling urine and ready for action. Once in an all-male group, a young bull’s musth-driven aggression (fighting and mounting everyone in sight) will be met by shoves and head butting from his elders. O’Connell hypothesizes that such disciplinary action may cause “socially induced hormone suppression,” as happens with other species.
It doesn’t always work, and a couple of the book’s most dramatic chapters describe challenges to the don’s authority by low-ranking but high-testosterone young bulls. There is also a period when most of Greg’s entourage disintegrates under the stress of a drought, partially reassembling around his leadership when conditions improve later.
Giving the elephants human names, while a matter of convenience in recording their behavior, is already a step towards anthropomorphizing them, and the process is irreversible once you add narrative. That’s fine in popular exposition, since the stories O’Connell has to tell -- both about the elephants and about life in the field, with poisonous snakes and infrequent access to a shower -- are certainly absorbing.
But I wondered for a while if the ascriptions of personality and motive to her “pachyderm posse” might not embellish things beyond credibility. Only halfway through the book do we get a chapter reviewing scientific findings about elephants’ cognitive powers -- pages that put the question in a new light.
Seismic communication itself is pretty impressive, but elephants also have the capacity to solve problems (say, by throwing rocks or an uprooted tree onto an electrified fence to disable it) and to fine-tune tools: “In one study, for example, elephants were shown to use their highly muscular prehensile trunks to modify branches for optimum use as switches to repel flies.” Their proverbial memory may be superior to that of humans, and experiments have shown them to be able to understand iconic symbols and to remember distinctions for long periods.
So the possibility that they have rituals and a social order is not, on the whole, that much of a stretch. It’s enough to make you wonder what they think of us, assuming they even bother.